.header {
    display: flex; //flex布局
    margin-bottom: 20px;
    .left {
        flex: 1;
        h3 {
            margin: 0!important;
        }
    }
    .right {
        flex: 1;
        text-align: right;
    }
}

.container {
    margin-bottom: 20px;
}

.footer {
    text-align: center;
}